This is one of the most important questions for any age. Most people do not even care to ask this question and hence their life is so miserably small regardless of their outer achievements.
This question can be covered in two parts. The first is the general answer to the goal of human life for all of us, and the second is more specific to each one of us. So let us start with the first. Well, so we are told that God, the ultimate Source of all we are is within us. The general goal therefore would be to find and manifest Him, to express God in all we think and feel and do. This would apply to all.
Now the personal goal means the path that each one must take to do this. Here again there are two aspects. First is the inner path which means we must find our own unique way to connect with God. This is discovered by studying ourselves carefully and finding what kind of approach suits us best. What makes us feel closer to the Divine Mother and what makes us feel far from Her. The second is outer and by that is meant what work or occupation makes us feel more deeply connected and helps us move closer and express Her better in our lives. The sign is a growing feeling of Peace and Joy when we undertake this work. It should flow naturally from us without much effort and with spontaneous ease. Later one can perfect it. But the initial impulsion should come from this careful study of our tastes and tendencies. This is called swadharma in the Gita.
When the path and the goal are perfectly aligned then life grows beautiful. When they are not due to the intrusion of ambition and desire for excess money, name and fame, worldly success then the original file of life gets corrupted and life does not yield its best or highest fruits.
To put it in a more general way is that the purpose of life is to progress towards perfection. But to know what this progress and perfection mean we should study, read, reflect and understand the words of those who have striven for perfection and found the path that takes us towards that and the way to progress. Otherwise we will be misled by many voices. That is why we need faith in the Guru and in those who are walking the path for long.